It is generally known that a porous outer surface can be used on an implantable medical device to promote bone ingrowth to facilitate device anchoring. It has also been suggested that the application of a porous surface to a percutaneous implantable device can be helpful for promoting tissue ingrowth. For example, see European Patent Publication 0367354B1 published Sep. 5, 1990 entitled “A percutaneous implant”. It is also noted that so called “dacron cuffs” have been used to accommodate tissue ingrowth for anchoring percutaneous catheters.